I've been surprised to learn how high the NOACK test percentage of mass lost is for both T5 and T6.Even PP in the 0W-20 grade puts either of these HDEOs on the trailer when it comes to percentage of mass lost in the NOACK test.Can someone help me to understand that the obvious conclusion that these oils are made of inferior basestock blends is wrong?

I have heard the opposite. T6 is praised in the Subaru and turbo car community as an oil that prevents burning and helps condition turbo seals. Give t6 and Subaru a Google and you will see what I'm talking about.

I have heard the opposite. T6 is praised in the Subaru and turbo car community as an oil that prevents burning and helps condition turbo seals. Give t6 and Subaru a Google and you will see what I'm talking about.

I heard the same thing, but then I saw actual test results on the PQIA website...unfortunately, these are from 2014 and I believe that T6 has been reformulated since then. This report was fairly new when I first looked at T6.

Never had a relationship between NOACK and oil burn-off in a passenger car.

Bingo. Even in really high Noack oils back in the day with the taxis, some burned, some didn't. Sure, a lower Noack might be "better," but we do have to be cautious how much we hang our hats on one number only.

If someone's really worried about Noack, just run a monograde. There will never be a concern about Noack. Everything else might be haywire, but the Noack will be right.

Garak, you're right in that NOACK isn't the only metric to consider in a motor oil, but it may be among the more important ones.NOACK does tell a user a lot about the quality of the basestocks used in formulating an oil.

I don't doubt its importance, but we have to watch what we divine out of that. Mola has posted months ago that there are ways to get some impressive Noacks without fantastic base stocks. Like I said, run a monograde, and you'll have a fantastic Noack.

When it comes to HDEOs, while I'm no formulator, perhaps there aren't many overriding reasons to go wild on getting the Noack down to what we see with some of the A3/B4 type oils with OEM certifications.

I use T6 in my 2006 Duramax I usually change oil it in a 5500 to 6000 mile range. I have never had to add oil between changes. In fact I don't remember ever having a real drop on the dip stick ever? I use it most to tow a 14,000 lbs. fifthweel. Because of the towing I never go for extended OCI's

I use T6 in my 2006 Duramax I usually change oil it in a 5500 to 6000 mile range. I have never had to add oil between changes. In fact I don't remember ever having a real drop on the dip stick ever? I use it most to tow a 14,000 lbs. fifthweel. Because of the towing I never go for extended OCI's

You're changing your oil way to often. You can easily go 10k using that oil and towing that trailer. That oil is rated for 80,000 miles in OTR trucks. We used standard Rotella 15w-40 in our Duramax at work, 10k oil changes and we still got 300,000 miles out of them, and thats as a delivery van fully loaded foot to the floor stop and go all day 5 days a week drive it like your stole it.

Spike this year the truck has seen very few miles a little over 2k all towing it will be a year in October. The Oil monitor says 80%. The fuel filter I skipped last year and it shows at 50% I will likely change them both out along with a new Air intake filter the end of October. Just got the AC/Delco fuel filter their coming down used to be $32 got this last one for $19 and some change. The total cost oil, a Fram Ultra Guard filter and the fuel filter is going to run me $79.90. Less than just an oil change at the dealer for mineral oil.